The present invention relates to electrical connectors, and more particularly to a female terminal having a selectively operable zero insertion force mechanism for zero force insertion and removal of a male terminal with respect thereto.
Electrical connectors generally have two metallic engaging terminals which must be in intimate contact for a good electrical connection therebetween to be maintained over the life of the connection. The intimate contact may be by a permanent affixment, as for example by a threaded fastener or a weld. However, for many purposes the connection must be selectively reversible. One connector configuration which serves this purpose is a male terminal (as for example in the form of a pin or a blade) and a female terminal configured for receiving therein the male terminal. An example of a female terminal and male terminal combination configured for selectively reversible connection is depicted at FIGS. 1 through 2B, and is indicative of a xe2x80x9cMetri-Packxe2x80x9d connection system of Delphi Technologies, Inc. of Troy, Mich.
As shown at FIG. 1, the female terminal 10 has a generally rectangular barrel 12 at one end and wire affixment features 14, 16 at the other end. Referring now additionally to FIG. 2A, it is further seen that a tongue 18 is located at the opening 20 and interior of the barrel 12. The tongue is connected to a floor 22 of the barrel 12, extends outwardly from the opening 20, then curves inwardly and upwardly so that an interface surface 24 of the tongue 18 is generally located at the roof 26 of the barrel 12. Pressure tabs 28 are located at a medial location of the tongue 18 and face toward the floor 22.
Referring now additionally to FIG. 2B, as a male terminal 30, which may be for example a blade (as shown) or a pin, is inserted into the opening 20 along arrow A, the male terminal encounters the interface surface 24 of the tongue 18, and in order for its continued insertion to be achieved, the tongue must be resiliently forced downwardly along arrow B by the male terminal. When the male terminal 10 is fully seated inside the barrel 12, the tongue applies sufficient resilience force upwardly along arrow C to cause an excellent intimate electrical contact between the male terminal and the interface surface (which is, for example, tin plated).
A disadvantage of the female terminal 10 is that a large terminal engagement force is required during mating because of the necessity of the male terminal to force resilient bending of the tongue. Disadvantageously, repeated insertions/removals of the male terminal results in wear of the plating of the mutually abutting surfaces subjected to the tongue normal force.
Accordingly, it would be beneficial if somehow the male terminal could be inserted into the female terminal with zero terminal insertion force and zero contact between the male terminal and the tongue.
The present invention is a zero terminal insertion force electrical connection assembly featuring zero terminal insertion force during mating of a male and female terminal combination.
The female terminal according to the present invention features a barrel having a floor, a roof and an opening. The roof has an aperture formed therein. Connected to the floor is a tongue which extends outwardly from the opening and then curves inwardly and upwardly into the barrel. The tongue has an interface surface located adjacent the roof when the tongue is in a relaxed state. A boss feature is connected to the tongue adjacent the interface surface and extends uptandingly though the aperture in the roof when the tongue is in the relaxed state.
A zero insertion force member is slidably interfaced with the barrel such that at a first position, the boss feature projects fully through the aperture. However, when slid to a second position, the zero insertion force member presses upon the boss feature so as to cause the interface surface of the tongue to be resiliently depressed toward the floor. Accordingly, when the zero insertion/extraction force member is at the second position, a male terminal may be slid receivingly into the barrel through the opening and be fully received without any contact with the tongue. As a result of the cooperative interaction of the boss feature and the zero insertion force member, the insertion and removal of the male terminal with respect to the female terminal is accomplished without terminal insertion force and without scrapping between the male terminal and the tongue. Yet, when the zero insertion force member is returned to the first position, the tongue resiliently rebounds so that the interface surface of the tongue comes into good abutting electrical contact with the male terminal by virtue of the resilient normal force of the tongue.
Accordingly, it is an object of the present invention to provide an electrical connection between two electrical terminals in which zero terminal insertion force is involved.
It is an additional object of the present invention to provide an electrical connection between two electrical terminals in which zero terminal insertion force is involved and wherein the mating and unmating of the terminals is accomplishable without scrapping between the electrical contact surfaces.
These and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment.